The integrability of our matrix model allows one to define immediately the quantum spectral curve as an operator which cancels the Baker–Akhiezer function of the integrable system [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}. Indeed, in our Toda chain case, the latter is defined through the \(\tau \) -function (the matrix model partition function) as (in this subsection \(V\)  denotes the potential with shifted coefficients, i.e., is a sum of \(W+V\)  in (REF ), and all the statements are treated in terms of formal series in \(V\) )
\(\Psi _{\rm BA}(z)={\rm e}^{V(z)/2}\Psi (z),\) 
